Method for weaving endless belts



1957 B. J. WILLMANN 3,306,322

METHOD FOR WEAVING ENDLESS BELTS Filed March 8, 1965 I 2 Sheets-Sheet 1 F'iled March a, 1965 Feb. 28, 1967 B. J. WILLMANN 3,306,322

METHOD FOR WEAVING ENDLESS BELTS 2 Sheefs-Sheet 2 3,306,322 Patented Feb. 28, 1967 67,3 1 Claim. 01. 139-20 The present invention relates to methods of making endless belts woven from plastic threads and metallic threads.

The invention is more especially but not exclusively concerned with methods for the production of belts for supporting a material to be dried, which is the case in particular with belts used in paper making machines and called Fourdrinier cloths.

The object of the present invention is to provide a method capable of complying with the requirements of practice and in particular such that said belts have in the direction perpendicular to the loop-shaped edges of the endless belt a rigidity greater than that in the direction parallel to the loop-shaped edges of the endless belt.

In the looms used up to now, it is known directly to produce a woven endless belt the loop-shaped cross section of which is predetermined and the length of which (in the direction perpendicular to said cross section) increases as the weaving operation is proceeding, the transverse threads (perpendicular to said loop-shaped cross section being the warp threads and the longitudinal thread (extending parallel to said cross section) being the weft thread.

The present invention consists essentially in using, on the one hand, as weft thread, a plastic thread incorporated into the woven belt that is being made by the throwing of the shuttle into the open shed (space comprised between two lines of warp threads previously moved away from each other) and, on the other hand, as weft threads, both plastic threads and metallic threads coming respectively from two independent beams from which said weft threads are unwound, said metallic threads forming so to speak the skeleton of the endless belt and serving in particular to reinforce the transverse rigidity of said belt.

A preferred embodiment of the present invention will be hereinafter described with reference to the appended drawings, given merely by way of example, and in which:

FIG. 1 is a perspective view diagrammatically showing the essential elements of a loom for making endless belts according to the present invention;

FIG. la shows, on an enlarged scale and in longitudinal section (parallel to the edges of the belt) the portion of the endless belt that is being made on the machine of FIG. 1;

FIG. 2 is a perspective view of a portion of the endless belt.

In the following description, it will be supposed that the invention serves to the manufacture of an endless belt with plastic threads and metallic threads for a paper making machine, for instance of a belt of relatively great width and having relatively thin meshes.

Use is made, for weaving this belt, of a loom permitting the direct production of a belt of predetermined length and of a width which increases as the weaving operation is proceeding, the essential elements of a loom of this kind, and also an endless belt B in the way of manufacture, being diagrammatically shown in FIG. 1.

According to the main feature of the invention, use is made, as shown by the drawings:

On the one hand, as weft thread, of a plastic thread 1 incorporated in the belt B that is being made by the reciprocating movement of a shuttle (not shown) in open shed F; and

On the other hand, as warp threads, of both plastic threads 2a (shown in white in FIG. 1a) and metallic threads 217 (shown in black in FIG. 1a) coming respectively from two independent beams 3a and 3b capable of working at different respective speeds, said metallic threads being incorporated in suitable proportions (every second one, every third one, etc.) according to the fineness of the cloth to be obtained and to the desired degree of transverse rigidity.

It should be noted that the rule for interweaving the warp threads with the weft threads may vary within wide limits.

Anyway, whatever be the proportion of the metallic warp threads 2b with respect to the plastic warp threads 20!, and the kind of weaving that is chosen, such a method of making endless belt B permits, by acting upon the tension of the sheet of metallic warp threads 2b, for instance by adjusting the braking means which control the unwinding speed of beam 3b, of adjusting the evolution of said metallic threads with respect to the plastic warp threads 2a and also with respect to the plastic weft threads 1.

Thus, in particular, by tensioning the metallic threads substantially more than the plastic threads, it is possible to obtain that said metallic threads constitute, in the finished fabric, a substantially flat sheet on either side of which project the plastic threads which are then the only ones to come into contact with the hard elements of the paper making machine, in particular of the Fourdrinier table, upon which the endless belt is bearing during its utilization.

Thus, the plastic threads are the only ones to be subjected to an abrasion which they better withstand than the metallic threads whereby the latter undergo practically no friction wear.

In these conditions, the transverse rigidity of the endless belt, which rigidity depends upon the proportion of metallic threads incorporated in the warp during weaving and upon the diameter of said threads, will practically not vary during the life of said endless belt since said metallic threads are protected against any premature wear by the plastic threads projecting on either side of the flat sheet formed by said metallic threads.

A weaving loom according to the present invention for the production of belt B will be described with reference to FIG. 1. This loom comprises in particular heddles 4-, lease rods 5, a movable whip roll 6, rolls 7, which are not stationarily mounted, and a batten provided with a reed (not shown in order not to complicate the drawings) located opposite the open shed F.

The operation and advantages of a machine according to the present invention result from the foregoing description.

In a general manner, while the above description discloses what is deemed to be a pactical embodiment of the invention, said invention is not limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the invention as comprehended within the scope of the appended claim.

What I claim is:

A method of making an endless belt the length of the loop-shaped sections of which is fixed and the length of which in a direction transverse to said loop-shaped sections increases as weaving proceeds, which comprises weaving said belt from sheets of parallel warp threads some of which are made of a plastic material while the others, interspaced at regular intervals among said plastic material warp threads, are metallic and from a plastic material weft thread, repeatedly throwing said Weft thread 10 across said warp threads to weave it with them, and maintaining the warp threads under tension with a greater tension being constantly applied to the metallic warp threads than to the plastic material warp threads.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 11/1965 Canada.

MERVIN STEIN, Primary Examiner.

H, S. JAUDON, Assistant Examiner. 

